nhaliday + control   13

The Long-run Effects of Agricultural Productivity on Conflict, 1400-1900∗
This paper provides evidence of the long-run effects of a permanent increase in agricultural productivity on conflict. We construct a newly digitized and geo-referenced dataset of battles in Europe, the Near East and North Africa covering the period between 1400 and 1900 CE. For variation in permanent improvements in agricultural productivity, we exploit the introduction of potatoes from the Americas to the Old World after the Columbian Exchange. We find that the introduction of potatoes permanently reduced conflict for roughly two centuries. The results are driven by a reduction in civil conflicts

http://marginalrevolution.com/marginalrevolution/2017/12/monday-assorted-links-135.html#comment-159746885
#4 An obvious counterfactual is of course the potato blight (1844 and beyond) in Europe. Here’s the Wikipedia page ‘revolutions of 1848’ https://en.wikipedia.org/wiki/Revolutions_of_1848
pdf  study  marginal-rev  economics  broad-econ  cliometrics  history  medieval  early-modern  age-of-discovery  branches  innovation  discovery  agriculture  food  econ-productivity  efficiency  natural-experiment  europe  the-great-west-whale  MENA  war  revolution  peace-violence  trivia  cocktail  stylized-facts  usa  endogenous-exogenous  control  geography  cost-benefit  multi  econotariat  links  poast  wiki  reference  events  roots 
december 2017 by nhaliday
The Power of Abortion Policy - Marginal REVOLUTION
I provide new evidence on the relative “powers” of contraception and abortion policy in effecting the dramatic social transformations of the 1960s and 1970s. Trends in sexual behavior suggest that young women’s increased access to the birth control pill fueled the sexual revolution, but neither these trends nor difference-in-difference estimates support the view that this also led to substantial changes in family formation. Rather, the estimates robustly suggest that it was liberalized access to abortion that allowed large numbers of women to delay marriage and motherhood.
econotariat  marginal-rev  commentary  study  summary  economics  policy  intervention  sociology  gender  sex  fertility  demographics  demographic-transition  history  mostly-modern  cold-war  rot  roots  explanans  technology  microfoundations  nitty-gritty  sexuality  modernity  the-bones  general-survey  endogenous-exogenous  control  life-history  social-norms  medicine  abortion-contraception-embryo 
december 2017 by nhaliday
Autocratic Rule and Social Capital: Evidence from Imperial China by Melanie Meng Xue, Mark Koyama :: SSRN
This paper studies how autocratic rule affects social capital. Between 1660-1788, individuals in imperial China were persecuted if they were suspected of holding subversive attitudes towards the state. A difference-in-differences approach suggests that these persecutions led to a decline of 38% in social capital, as measured by the number of charitable organizations, in each subsequent decade. Investigating the long-run effect of autocratic rule, we show that persecutions are associated with lower levels of trust, political engagement, and the under provision of local public goods. These results indicate a possible vicious cycle in which autocratic rule becomes self-reinforcing through a permanent decline in social capital.
study  economics  broad-econ  econotariat  history  early-modern  growth-econ  authoritarianism  antidemos  china  asia  sinosphere  orient  n-factor  social-capital  individualism-collectivism  charity  cliometrics  trust  cohesion  political-econ  polisci  public-goodish  correlation  intervention  unintended-consequences  iteration-recursion  cycles  effect-size  path-dependence  🎩  leviathan  endogenous-exogenous  control  branches  pseudoE  slippery-slope  counter-revolution  nascent-state  microfoundations  explanans  the-great-west-whale  occident  madisonian  hari-seldon  law  egalitarianism-hierarchy  local-global  decentralized  the-watchers  noblesse-oblige  benevolence 
september 2017 by nhaliday
Fear and Loathing in Psychology - The Unz Review
Warne and Astle looked at 29 best-selling undergraduate textbooks, which is where psychology students learn about intelligence, because less than 10% of graduate courses offer an intelligence option.

3.3% of textbook space is dedicated to intelligence. Given its influence, this is not very much.

The most common topics start well, with IQ and Spearman’s g, but do not go on to the best validated, evidence-led Cattell-Horn-Carol meta-analytic summary, but a side-stream, speculative triarchic theory from Sternberg; and a highly speculative and non-specific sketch of an idea about multiple intelligences Gardner. The last is a particular puzzle, since it really is a whimsical notion that motor skill is no different from analytical problem solving. All must have prizes.
Commonly, environmental influences are discussed, genetic ones rarely.

What Do Undergraduates Learn About Human Intelligence? An Analysis of Introductory Psychology Textbooks: https://drive.google.com/file/d/0B3c4TxciNeJZOTl3clpiX0JKckk/view

Education or Indoctrination? The Accuracy of Introductory Psychology Textbooks in Covering Controversial Topics and Urban Legends About Psychology: http://sci-hub.la/https://link.springer.com/article/10.1007/s12144-016-9539-7

Twenty-four leading introductory psychology textbooks were surveyed for their coverage of a number of controversial topics (e.g., media violence, narcissism epidemic, multiple intelligences) and scientific urban legends (e.g., Kitty Genovese, Mozart Effect) for their factual accuracy. Results indicated numerous errors of factual reporting across textbooks, particularly related to failing to inform students of the controversial nature of some research fields and repeating some scientific urban legends as if true. Recommendations are made for improving the accuracy of introductory textbooks.

Mapping the scale of the narcissism epidemic: Increases in narcissism 2002–2007 within ethnic groups: https://www.sciencedirect.com/science/article/pii/S0092656608000949

The increasing numbers of Asian-Americans at the UCs over time may have masked changes in narcissism, as Asian-Americans score lower on the NPI. When examined within ethnic groups, Trzesniewski et al.’s data show that NPI scores increased significantly between 2002 and 2007 at twice the rate of the yearly change found over 24 years in Twenge et al. (2008a). The overall means also show a significant increase 2002–2007. Thus the available evidence suggests that college students are endorsing progressively more narcissistic personality traits over the generations.

Birth Cohort Increases in Narcissistic Personality Traits Among American College Students, 1982–2009: http://journals.sagepub.com/doi/abs/10.1177/1948550609355719

Both studies demonstrate significant increases in narcissism over time (Study 1 d = .37, 1982–2008, when campus is controlled; Study 2 d = .37, 1994–2009). These results support a generational differences model of individual personality traits reflecting changes in culture.

could this just be a selection effect (more people attending)?
albion  scitariat  education  higher-ed  academia  social-science  westminster  info-dynamics  psychology  cog-psych  psychometrics  iq  intelligence  realness  biases  commentary  study  summary  meta:science  pinker  multi  pdf  survey  is-ought  truth  culture-war  toxoplasmosis  replication  social-psych  propaganda  madisonian  identity-politics  init  personality  psychiatry  disease  trends  epidemiology  public-health  psych-architecture  dimensionality  confounding  control  age-generation  demographics  race  christopher-lasch  humility  usa  the-west  california  berkeley  asia 
july 2017 by nhaliday
Econometric Modeling as Junk Science
The Credibility Revolution in Empirical Economics: How Better Research Design Is Taking the Con out of Econometrics: https://www.aeaweb.org/articles?id=10.1257/jep.24.2.3

On data, experiments, incentives and highly unconvincing research – papers and hot beverages: https://papersandhotbeverages.wordpress.com/2015/10/31/on-data-experiments-incentives-and-highly-unconvincing-research/
In my view, it has just to do with the fact that academia is a peer monitored organization. In the case of (bad) data collection papers, issues related to measurement are typically boring. They are relegated to appendices, no one really has an incentive to monitor it seriously. The problem is similar in formal theory: no one really goes through the algebra in detail, but it is in principle feasible to do it, and, actually, sometimes these errors are detected. If discussing the algebra of a proof is almost unthinkable in a seminar, going into the details of data collection, measurement and aggregation is not only hard to imagine, but probably intrinsically infeasible.

Something different happens for the experimentalist people. As I was saying, I feel we have come to a point in which many papers are evaluated based on the cleverness and originality of the research design (“Using the World Cup qualifiers as an instrument for patriotism!? Woaw! how cool/crazy is that! I wish I had had that idea”). The sexiness of the identification strategy has too often become a goal in itself. When your peers monitor you paying more attention to the originality of the identification strategy than to the research question, you probably have an incentive to mine reality for ever crazier discontinuities. It is true methodologists have been criticized in the past for analogous reasons, such as being guided by the desire to increase mathematical complexity without a clear benefit. But, if you work with pure formal theory or statistical theory, your work is not meant to immediately answer question about the real world, but instead to serve other researchers in their quest. This is something that can, in general, not be said of applied CI work.

https://twitter.com/pseudoerasmus/status/662007951415238656
This post should have been entitled “Zombies who only think of their next cool IV fix”
https://twitter.com/pseudoerasmus/status/662692917069422592
massive lust for quasi-natural experiments, regression discontinuities
barely matters if the effects are not all that big
I suppose even the best of things must reach their decadent phase; methodological innov. to manias……

https://twitter.com/cblatts/status/920988530788130816
Following this "collapse of small-N social psych results" business, where do I predict econ will collapse? I see two main contenders.
One is lab studies. I dallied with these a few years ago in a Kenya lab. We ran several pilots of N=200 to figure out the best way to treat
and to measure the outcome. Every pilot gave us a different stat sig result. I could have written six papers concluding different things.
I gave up more skeptical of these lab studies than ever before. The second contender is the long run impacts literature in economic history
We should be very suspicious since we never see a paper showing that a historical event had no effect on modern day institutions or dvpt.
On the one hand I find these studies fun, fascinating, and probably true in a broad sense. They usually reinforce a widely believed history
argument with interesting data and a cute empirical strategy. But I don't think anyone believes the standard errors. There's probably a HUGE
problem of nonsignificant results staying in the file drawer. Also, there are probably data problems that don't get revealed, as we see with
the recent Piketty paper (http://marginalrevolution.com/marginalrevolution/2017/10/pikettys-data-reliable.html). So I take that literature with a vat of salt, even if I enjoy and admire the works
I used to think field experiments would show little consistency in results across place. That external validity concerns would be fatal.
In fact the results across different samples and places have proven surprisingly similar across places, and added a lot to general theory
Last, I've come to believe there is no such thing as a useful instrumental variable. The ones that actually meet the exclusion restriction
are so weird & particular that the local treatment effect is likely far different from the average treatment effect in non-transparent ways.
Most of the other IVs don't plausibly meet the e clue ion restriction. I mean, we should be concerned when the IV estimate is always 10x
larger than the OLS coefficient. This I find myself much more persuaded by simple natural experiments that use OLS, diff in diff, or
discontinuities, alongside randomized trials.

What do others think are the cliffs in economics?
PS All of these apply to political science too. Though I have a special extra target in poli sci: survey experiments! A few are good. I like
Dan Corstange's work. But it feels like 60% of dissertations these days are experiments buried in a survey instrument that measure small
changes in response. These at least have large N. But these are just uncontrolled labs, with negligible external validity in my mind.
The good ones are good. This method has its uses. But it's being way over-applied. More people have to make big and risky investments in big
natural and field experiments. Time to raise expectations and ambitions. This expectation bar, not technical ability, is the big advantage
economists have over political scientists when they compete in the same space.
(Ok. So are there any friends and colleagues I haven't insulted this morning? Let me know and I'll try my best to fix it with a screed)

HOW MUCH SHOULD WE TRUST DIFFERENCES-IN-DIFFERENCES ESTIMATES?∗: https://economics.mit.edu/files/750
Most papers that employ Differences-in-Differences estimation (DD) use many years of data and focus on serially correlated outcomes but ignore that the resulting standard errors are inconsistent. To illustrate the severity of this issue, we randomly generate placebo laws in state-level data on female wages from the Current Population Survey. For each law, we use OLS to compute the DD estimate of its “effect” as well as the standard error of this estimate. These conventional DD standard errors severely understate the standard deviation of the estimators: we find an “effect” significant at the 5 percent level for up to 45 percent of the placebo interventions. We use Monte Carlo simulations to investigate how well existing methods help solve this problem. Econometric corrections that place a specific parametric form on the time-series process do not perform well. Bootstrap (taking into account the auto-correlation of the data) works well when the number of states is large enough. Two corrections based on asymptotic approximation of the variance-covariance matrix work well for moderate numbers of states and one correction that collapses the time series information into a “pre” and “post” period and explicitly takes into account the effective sample size works well even for small numbers of states.

‘METRICS MONDAY: 2SLS–CHRONICLE OF A DEATH FORETOLD: http://marcfbellemare.com/wordpress/12733
As it turns out, Young finds that
1. Conventional tests tend to overreject the null hypothesis that the 2SLS coefficient is equal to zero.
2. 2SLS estimates are falsely declared significant one third to one half of the time, depending on the method used for bootstrapping.
3. The 99-percent confidence intervals (CIs) of those 2SLS estimates include the OLS point estimate over 90 of the time. They include the full OLS 99-percent CI over 75 percent of the time.
4. 2SLS estimates are extremely sensitive to outliers. Removing simply one outlying cluster or observation, almost half of 2SLS results become insignificant. Things get worse when removing two outlying clusters or observations, as over 60 percent of 2SLS results then become insignificant.
5. Using a Durbin-Wu-Hausman test, less than 15 percent of regressions can reject the null that OLS estimates are unbiased at the 1-percent level.
6. 2SLS has considerably higher mean squared error than OLS.
7. In one third to one half of published results, the null that the IVs are totally irrelevant cannot be rejected, and so the correlation between the endogenous variable(s) and the IVs is due to finite sample correlation between them.
8. Finally, fewer than 10 percent of 2SLS estimates reject instrument irrelevance and the absence of OLS bias at the 1-percent level using a Durbin-Wu-Hausman test. It gets much worse–fewer than 5 percent–if you add in the requirement that the 2SLS CI that excludes the OLS estimate.

Methods Matter: P-Hacking and Causal Inference in Economics*: http://ftp.iza.org/dp11796.pdf
Applying multiple methods to 13,440 hypothesis tests reported in 25 top economics journals in 2015, we show that selective publication and p-hacking is a substantial problem in research employing DID and (in particular) IV. RCT and RDD are much less problematic. Almost 25% of claims of marginally significant results in IV papers are misleading.

https://twitter.com/NoamJStein/status/1040887307568664577
Ever since I learned social science is completely fake, I've had a lot more time to do stuff that matters, like deadlifting and reading about Mediterranean haplogroups
--
Wait, so, from fakest to realest IV>DD>RCT>RDD? That totally matches my impression.
org:junk  org:edu  economics  econometrics  methodology  realness  truth  science  social-science  accuracy  generalization  essay  article  hmm  multi  study  🎩  empirical  causation  error  critique  sociology  criminology  hypothesis-testing  econotariat  broad-econ  cliometrics  endo-exo  replication  incentives  academia  measurement  wire-guided  intricacy  twitter  social  discussion  pseudoE  effect-size  reflection  field-study  stat-power  piketty  marginal-rev  commentary  data-science  expert-experience  regression  gotchas  rant  map-territory  pdf  simulation  moments  confidence  bias-variance  stats  endogenous-exogenous  control  meta:science  meta-analysis  outliers  summary  sampling  ensembles  monte-carlo  theory-practice  applicability-prereqs  chart  comparison  shift  ratty  unaffiliated 
june 2017 by nhaliday
Democracy does not cause growth | Brookings Institution
64-page paper
Democracy & Growth: http://www.nber.org/papers/w4909
The favorable effects on growth include maintenance of the rule of law, free markets, small government consumption, and high human capital. Once these kinds of variables and the initial level of real per-capita GDP are held constant, the overall effect of democracy on growth is weakly negative. There is a suggestion of a nonlinear relationship in which democracy enhances growth at low levels of political freedom but depresses growth when a moderate level of freedom has already been attained.

The growth effect of democracy: Is it heterogenous and how can it be estimated∗: http://perseus.iies.su.se/~tpers/papers/cifar_paper_may16_07.pdf
In particular, we find an average negative effect on growth of leaving democracy on the order of −2 percentage points implying effects on income per capita as large as 45 percent over the 1960-2000 panel. Heterogenous characteristics of reforming and non-reforming countries appear to play an important role in driving these results.

Does democracy cause innovation? An empirical test of the popper hypothesis: http://www.sciencedirect.com.sci-hub.cc/science/article/pii/S0048733317300975
The results from the difference-in-differences method show that democracy itself has no direct positive effect on innovation measured with patent counts, patent citations and patent originality.

Benevolent Autocrats: https://williameasterly.files.wordpress.com/2011/09/benevolent-autocrats-easterly-draft.pdf
A large literature attributes this to the higher variance of growth rates under autocracy than under democracy. The literature offers alternative explanations for this stylized fact: (1) leaders don’t matter under democracy, but good and bad leaders under autocracy cause high and low growth, (2) leaders don’t matter under autocracy either, but good and bad autocratic systems cause greater extremes of high and low growth, or (3) democracy does better than autocracy at reducing variance from shocks from outside the political system. This paper details further the stylized facts to test these distinctions. Inconsistent with (1), the variance of growth within the terms of leaders swamps the variance across leaders, and more so under autocracy than under democracy. Country effects under autocracy are also overwhelmed by within-country variance, inconsistent with (2). Explanation (3) fits the stylized facts the best of the three alternatives.

Political Institutions, Size of Government and Redistribution: An empirical investigation: http://www.lse.ac.uk/internationalDevelopment/pdf/WP/WP89.pdf
Results show that the stronger democratic institutions are, the lower is government size and the higher the redistributional capacity of the state. Political competition exercises the strongest and most robust effect on the two variables.

https://twitter.com/GarettJones/status/899466295170801664
https://archive.is/sPFII
Fits the high-variance theory of autocracies:
More miracles, more disasters. And there's a lot of demand for miracles.

Measuring the ups and downs of governance: https://www.brookings.edu/blog/future-development/2017/09/22/measuring-the-ups-and-downs-of-governance/
Figure 2: Voice and Accountability and Government Effectiveness, 2016
https://twitter.com/whyvert/status/917444456386666497
https://archive.is/EBQlD
Georgia, Japan, Rwanda, and Serbia ↑ Gov Effectiveness; Indonesia, Tunisia, Liberia, Serbia, and Nigeria ↑ Voice and Accountability.

The logic of hereditary rule: theory and evidence: http://eprints.lse.ac.uk/69615/
Hereditary leadership has been an important feature of the political landscape throughout history. This paper argues that hereditary leadership is like a relational contract which improves policy incentives. We assemble a unique dataset on leaders between 1874 and 2004 in which we classify them as hereditary leaders based on their family history. The core empirical finding is that economic growth is higher in polities with hereditary leaders but only if executive constraints are weak. Moreover, this holds across of a range of specifications. The finding is also mirrored in policy outcomes which affect growth. In addition, we find that hereditary leadership is more likely to come to an end when the growth performance under the incumbent leader is poor.

I noted this when the paper was a working paper, but non-hereditary polities with strong contraints have higher growth rates.
study  announcement  polisci  economics  macro  government  policy  contrarianism  hmm  econometrics  counterfactual  alt-inst  institutions  new-religion  thiel  political-econ  stylized-facts  🎩  group-level  longitudinal  c:**  2016  summary  realpolitik  wonkish  mostly-modern  democracy  org:ngo  ideology  definite-planning  social-choice  nascent-state  chart  madisonian  antidemos  cynicism-idealism  kumbaya-kult  whiggish-hegelian  multi  pdf  effect-size  authoritarianism  growth-econ  econ-metrics  wealth-of-nations  wealth  innovation  null-result  endo-exo  leviathan  civil-liberty  property-rights  capitalism  markets  human-capital  curvature  piracy  easterly  bias-variance  moments  outcome-risk  redistribution  welfare-state  white-paper  natural-experiment  correlation  history  cold-war  twitter  social  commentary  spearhead  econotariat  garett-jones  backup  gibbon  counter-revolution  data  visualization  plots  trends  marginal  scitariat  hive-mind  inequality  egalitarianism-hierarchy  world  developing-world  convexity-curvature  endogeno 
september 2016 by nhaliday
Divorce and children’s long-term outcomes | VOX, CEPR’s Policy Portal
It has been widely demonstrated that parental divorce is associated with negative outcomes for affected children. However, the degree of causality in this relationship is not as clear. This column tackles this problem by using the level of gender integration in fathers’ workplaces as an instrument for divorce. The results suggest a causal link between divorce and worse economic outcomes that persists into early adulthood.
http://ftp.iza.org/dp9928.pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3904543/
The literature on father absence is frequently criticized for its use of cross-sectional data and methods that fail to take account of possible omitted variable bias and reverse causality. We review studies that have responded to this critique by employing a variety of innovative research designs to identify the causal effect of father absence, including studies using lagged dependent variable models, growth curve models, individual fixed effects models, sibling fixed effects models, natural experiments, and propensity score matching models. Our assessment is that studies using more rigorous designs continue to find negative effects of father absence on offspring well-being, although the magnitude of these effects is smaller than what is found using traditional cross-sectional designs. The evidence is strongest and most consistent for outcomes such as high school graduation, children’s social-emotional adjustment, and adult mental health.

Genetics, the Rearing Environment, and the Intergenerational Transmission of Divorce: A Swedish National Adoption Study: http://journals.sagepub.com/doi/abs/10.1177/0956797617734864
There was stronger resemblance to lived-with mothers, providing indirect evidence of rearing-environment influences on the intergenerational transmission of divorce. The heritability of divorce assessed across generations was 0.13. We attempted to replicate our findings using within-generation data from adoptive and biological siblings (ns = 8,523–53,097). Adoptees resembled their biological, not adoptive, siblings in their history of divorce. Thus, there was consistent evidence that genetic factors contributed to the intergenerational transmission of divorce but weaker evidence for a rearing-environment effect of divorce. Within-generation data from siblings supported these conclusions.

The Long-Term Effects of Legalizing Divorce on Children: http://onlinelibrary.wiley.com/doi/10.1111/obes.12200/abstract
We find that women who grew up under legal divorce have lower earnings and income and worse health as adults compared with women who grew up under illegal divorce. These negative effects are not found for men.

Father Absence and Reproductive Strategy: An Evolutionary Perspective: http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1037&context=anthropologyfacpub
interesting fact: father-absent childhood raises verbal and lowers math/spatial aptitude

Relation of Type and Onset of Father Absence to Cognitive Development: http://sci-hub.tw/http://www.jstor.org/stable/1127548
gender  causation  study  parenting  regularizer  long-term  developmental  environmental-effects  biodet  natural-experiment  confounding  sociology  org:ngo  intervention  endo-exo  multi  pdf  gender-diff  article  life-history  white-paper  meta-analysis  survey  education  labor  stress  psychiatry  dignity  endogenous-exogenous  sib-study  behavioral-gen  europe  nordic  psychology  social-psych  roots  variance-components  genetics  science-anxiety  chart  branches  cost-benefit  institutions  social-structure  health  demographics  compensation  policy  law  control  west-hunter  scitariat  anthropology  evopsych  sex  sexuality  rot  coming-apart  social-norms  stylized-facts  correlation  🌞  tradeoffs  class  sapiens  speculation  iq  language  spatial  psych-architecture  history  mostly-modern  data  comparison  personality  things  world-war  direction  cultural-dynamics  usa  higher-ed  harvard  phalanges  piracy  gnosis-logos  dirty-hands  embodied  the-world-is-just-atoms  cog-psych  intelligence 
august 2016 by nhaliday
Information Processing: Evidence for (very) recent natural selection in humans
height (+), infant head circumference (+), some biomolecular stuff, female hip size (+), male BMI (-), age of menarche (+, !!), and birth weight (+)

Strong selection in the recent past can cause allele frequencies to change significantly. Consider two different SNPs, which today have equal minor allele frequency (for simplicity, let this be equal to one half). Assume that one SNP was subject to strong recent selection, and another (neutral) has had approximately zero effect on fitness. The advantageous version of the first SNP was less common in the far past, and rose in frequency recently (e.g., over the last 2k years). In contrast, the two versions of the neutral SNP have been present in roughly the same proportion (up to fluctuations) for a long time. Consequently, in the total past breeding population (i.e., going back tens of thousands of years) there have been many more copies of the neutral alleles (and the chunks of DNA surrounding them) than of the positively selected allele. Each of the chunks of DNA around the SNPs we are considering is subject to a roughly constant rate of mutation.

Looking at the current population, one would then expect a larger variety of mutations in the DNA region surrounding the neutral allele (both versions) than near the favored selected allele (which was rarer in the population until very recently, and whose surrounding region had fewer chances to accumulate mutations). By comparing the difference in local mutational diversity between the two versions of the neutral allele (should be zero modulo fluctuations, for the case MAF = 0.5), and between the (+) and (-) versions of the selected allele (nonzero, due to relative change in frequency), one obtains a sensitive signal for recent selection. See figure at bottom for more detail. In the paper what I call mutational diversity is measured by looking at distance distribution of singletons, which are rare variants found in only one individual in the sample under study.

The 2,000 year selection of the British: http://www.unz.com/gnxp/the-2000-year-selection-of-the-british/

Detection of human adaptation during the past 2,000 years: http://www.biorxiv.org/content/early/2016/05/07/052084

The key idea is that recent selection distorts the ancestral genealogy of sampled haplotypes at a selected site. In particular, the terminal (tip) branches of the genealogy tend to be shorter for the favored allele than for the disfavored allele, and hence, haplotypes carrying the favored allele will tend to carry fewer singleton mutations (Fig. 1A-C and SOM).

To capture this effect, we use the sum of distances to the nearest singleton in each direction from a test SNP as a summary statistic (Fig. 1D).

Figure 1. Illustration of the SDS method.

Figure 2. Properties of SDS.

Based on a recent model of European demography [25], we estimate that the mean tip length for a neutral sample of 3,000 individuals is 75 generations, or roughly 2,000 years (Fig. 2A). Since SDS aims to measure changes in tip lengths of the genealogy, we conjectured that it would be most likely to detect selection approximately within this timeframe.

Indeed, in simulated sweep models with samples of 3,000 individuals (Fig. 2B,C and fig. S2), we find that SDS focuses specifically on very recent time scales, and has equal power for hard and soft sweeps within this timeframe. At individual loci, SDS is powered to detect ~2% selection over 100 generations. Moreover, SDS has essentially no power to detect older selection events that stopped >100 generations before the present. In contrast, a commonly-used test for hard sweeps, iHS [12], integrates signal over much longer timescales (>1,000 generations), has no specificity to the more recent history, and has essentially no power for the soft sweep scenarios.

Catching evolution in the act with the Singleton Density Score: http://www.molecularecologist.com/2016/05/catching-evolution-in-the-act-with-the-singleton-density-score/
The Singleton Density Score (SDS) is a measure based on the idea that changes in allele frequencies induced by recent selection can be observed in a sample’s genealogy as differences in the branch length distribution.

You don’t need a weatherman: https://westhunt.wordpress.com/2016/05/08/you-dont-need-a-weatherman/
You can do a million cool things with this method. Since the effective time scale goes inversely with sample size, you could look at evolution in England over the past 1000 years or the past 500. Differencing, over the period 1-1000 AD. Since you can look at polygenic traits, you can see whether the alleles favoring higher IQs have increased or decreased in frequency over various stretches of time. You can see if Greg Clark’s proposed mechanism really happened. You can (soon) tell if creeping Pinkerization is genetic, or partly genetic.

You could probably find out if the Middle Easterners really have gotten slower, and when it happened.

Looking at IQ alleles, you could not only show whether the Ashkenazi Jews really are biologically smarter but if so, when it happened, which would give you strong hints as to how it happened.

We know that IQ-favoring alleles are going down (slowly) right now (not counting immigration, which of course drastically speeds it up). Soon we will know if this was true while Russia was under the Mongol yoke – we’ll know how smart Periclean Athenians were and when that boost occurred. And so on. And on!

...

“The pace has been so rapid that humans have changed significantly in body and mind over recorded history."

bicameral mind: https://westhunt.wordpress.com/2016/05/08/you-dont-need-a-weatherman/#comment-78934

https://westhunt.wordpress.com/2016/05/08/you-dont-need-a-weatherman/#comment-78939
Chinese, Koreans, Japanese and Ashkenazi Jews all have high levels of myopia. Australian Aborigines have almost none, I think.

https://westhunt.wordpress.com/2016/05/08/you-dont-need-a-weatherman/#comment-79094
I expect that the fall of all great empires is based on long term dysgenic trends. There is no logical reason why so many empires and civilizations throughout history could grow so big and then not simply keep growing, except for dysgenics.
--
I can think of about twenty other possible explanations off the top of my head, but dysgenics is a possible cause.
--
I agree with DataExplorer. The largest factor in the decay of civilizations is dysgenics. The discussion by R. A. Fisher 1930 p. 193 is very cogent on this matter. Soon we will know for sure.
--
Sometimes it can be rapid. Assume that the upper classes are mostly urban, and somewhat sharper than average. Then the Mongols arrive.
sapiens  study  genetics  evolution  hsu  trends  data  visualization  recent-selection  methodology  summary  GWAS  2016  scitariat  britain  commentary  embodied  biodet  todo  control  multi  gnxp  pop-diff  stat-power  mutation  hypothesis-testing  stats  age-generation  QTL  gene-drift  comparison  marginal  aDNA  simulation  trees  time  metrics  density  measurement  conquest-empire  pinker  population-genetics  aphorism  simler  dennett  👽  the-classics  iron-age  mediterranean  volo-avolo  alien-character  russia  medieval  spearhead  gregory-clark  bio  preprint  domestication  MENA  iq  islam  history  poast  west-hunter  scale  behavioral-gen  gotchas  cost-benefit  genomics  bioinformatics  stylized-facts  concept  levers  🌞  pop-structure  nibble  explanation  ideas  usa  dysgenics  list  applicability-prereqs  cohesion  judaism  visuo  correlation  china  asia  japan  korea  civilization  gibbon  rot  roots  fisher  giants  books  old-anglo  selection  agri-mindset  hari-seldon 
august 2016 by nhaliday
A Variant on “Statistically Controlling for Confounding Constructs is Harder than you Think”
It’s taken me some time to master this formalism, but I now find it quite easy to reason about these kinds of issues thanks to the brevity of graphical models as a notational technique. I’d love to see this approach become more popular in psychology, given that it has already become quite widespread in other fields. Of course, Westfall and Yarkoni are already advocating for something very similar by advocating for the use of SEM’s, but the graphical approach is strictly more general than SEM’s and, in my personal opinion, strictly simpler to reason about.
bayesian  stats  thinking  visualization  study  science  gelman  hmm  methodology  causation  acmtariat  meta:science  graphs  commentary  techtariat  hypothesis-testing  org:bleg  nibble  scitariat  confounding  🔬  info-dynamics  direct-indirect  volo-avolo  endo-exo  endogenous-exogenous  control  graphical-models 
may 2016 by nhaliday

related tags

abortion-contraception-embryo  academia  accuracy  acmtariat  aDNA  age-generation  age-of-discovery  agri-mindset  agriculture  albion  alien-character  alt-inst  announcement  anthropology  antidemos  aphorism  applicability-prereqs  article  asia  attaq  authoritarianism  backup  bayesian  behavioral-gen  benevolence  berkeley  bias-variance  biases  bio  biodet  bioinformatics  books  branches  britain  broad-econ  c:**  california  capitalism  causation  charity  chart  china  christopher-lasch  civil-liberty  civilization  class  cliometrics  cocktail  cog-psych  cohesion  cold-war  coming-apart  commentary  comparison  compensation  concept  confidence  confounding  conquest-empire  contrarianism  control  convexity-curvature  correlation  cost-benefit  counter-revolution  counterfactual  criminology  critique  cultural-dynamics  culture-war  curvature  cycles  cynicism-idealism  data  data-science  decentralized  definite-planning  democracy  demographic-transition  demographics  dennett  density  developing-world  developmental  dignity  dimensionality  direct-indirect  direction  dirty-hands  discovery  discussion  disease  domestication  dysgenics  early-modern  easterly  econ-metrics  econ-productivity  econometrics  economics  econotariat  education  effect-size  efficiency  egalitarianism-hierarchy  embodied  empirical  endo-exo  endogenous-exogenous  ensembles  environmental-effects  epidemiology  error  essay  europe  events  evidence-based  evolution  evopsych  expert-experience  explanans  explanation  fertility  field-study  fisher  food  garett-jones  gelman  gender  gender-diff  gene-drift  general-survey  generalization  genetics  genomics  geography  giants  gibbon  gnon  gnosis-logos  gnxp  gotchas  government  graphical-models  graphs  gregory-clark  group-level  growth-econ  GWAS  hanson  hari-seldon  harvard  health  healthcare  higher-ed  history  hive-mind  hmm  hsu  human-capital  humility  hypothesis-testing  ideas  identity-politics  ideology  impact  incentives  individualism-collectivism  inequality  info-dynamics  init  innovation  institutions  intelligence  intervention  intricacy  iq  iron-age  is-ought  islam  iteration-recursion  japan  jargon  judaism  korea  kumbaya-kult  labor  language  law  levers  leviathan  life-history  links  list  local-global  long-term  longitudinal  macro  madisonian  map-territory  marginal  marginal-rev  markets  measurement  medicine  medieval  mediterranean  MENA  mendel-randomization  meta-analysis  meta:science  methodology  metrics  microfoundations  modernity  moments  monte-carlo  mostly-modern  multi  mutation  n-factor  nascent-state  natural-experiment  new-religion  nibble  nitty-gritty  noblesse-oblige  nordic  null-result  occident  old-anglo  org:bleg  org:edu  org:junk  org:ngo  orient  outcome-risk  outliers  parenting  path-dependence  pdf  peace-violence  personality  phalanges  piketty  pinker  piracy  plots  poast  policy  polisci  political-econ  pop-diff  pop-structure  population-genetics  preprint  presentation  propaganda  property-rights  pseudoE  psych-architecture  psychiatry  psychology  psychometrics  public-goodish  public-health  QTL  race  rant  ratty  realness  realpolitik  recent-selection  redistribution  reference  reflection  regression  regularizer  replication  revolution  roots  rot  russia  sampling  sapiens  scale  science  science-anxiety  scitariat  selection  sex  sexuality  shift  sib-study  simler  simulation  sinosphere  slides  slippery-slope  social  social-capital  social-choice  social-norms  social-psych  social-science  social-structure  sociology  spatial  spearhead  speculation  stat-power  stats  stress  study  stylized-facts  sulla  summary  survey  talks  technology  techtariat  the-bones  the-classics  the-great-west-whale  the-watchers  the-west  the-world-is-just-atoms  theory-practice  thiel  things  thinking  time  todo  toxoplasmosis  tradeoffs  trees  trends  tricks  trivia  trust  truth  twitter  unaffiliated  unintended-consequences  usa  variance-components  visualization  visuo  volo-avolo  war  wealth  wealth-of-nations  welfare-state  west-hunter  westminster  whiggish-hegelian  white-paper  wiki  wire-guided  wonkish  world  world-war  🌞  🎩  👽  🔬 

Copy this bookmark:



description:


tags: